Protein from lizard embryos could advance cancer research

A protein key to the development of placenta in pregnant lizards may open the door to a promising new branch of cancer research.

Discovered by Sydney University biologist Bridget Murphy, the VEGF111 compound belongs to the so-called vascular endothelial growth factors (VEGFs) groups of proteins, which are key to the production of blood vessels in the uterus during pregnancy. They are also suspected of playing a role in the growth of cancer cells, which like embryos also require extensive networks of blood vessels.

With reptiles giving birth both to live young and eggs, Murphy became interested in identifying which VEGF proteins were active in lizards, eventually stumbling across the particularly powerful VEGF111 protein in the shy three-toed Australian skink saiphos equalis.

“I found that the three-toed skink, which gives birth to live young, uses a particularly powerful protein to encourage the growth of blood vessels,” Murphy said, adding that the only other place where VEGF111 has been found is in pre-cancerous cells in the laboratory.

It is hoped that by figuring out how this new protein functions researchers might develop new therapies for cancer as well as treatments for the regeneration of blood vessels in patients with heart disease and better approaches for tending wounds.

“Both tumours and embryos must develop an extensive network of blood vessels which bring in oxygen and nutrients to allow them to grow,” Murphy said.

“And they both must avoid rejection by hiding from the immune system of their host.”

Increasing numbes of researchers now suspect that cancers may have merely hijacked he molecular processes which originally evolved for the development of embryos.

“It may be that animals that give birth to live young, such as humans and some lizards, have an increased susceptibility to cancer,” Murphy said.

Murphy is one of 16 early-career Australian scientists selected to take part in the federal government’s Fresh Science program.